yellow/pink leaves

Training does nothing to "nutritional storage", it only involves the turning of the leaves back towards the light, something outdoor plants will do for 10-16 hours a day while they track the suns' movements and is a normal function. The symptoms your plants are showing and this early in the flowering phase, are usually associated with changing to bloom nutrients too early, as cannabis still needs adequate nitrogen in early-mid flower. Bloom nutrients should really only be started once small budlets or "tufts" of pistils have formed. Your plants are hungry for macro nutrients, - nitrogen, phosphorous and potassium (NPK). Try giving them a dose or two of half strength grow nutrients before changing back to half to three quarters strength bloom nutrients and this will top up the supplies of NPK and help your plants deal with the high demands of flowering better. Most fertilizers are too strong, mainly because the manufacturers want you and I (the customers) to be able to see that "something is happening" and half to three quarters strength is usually more than enough, especially when it comes to auto flowers. It is far better to feed less and slightly more often than it is to give high strength feeds less often. Frequent snacks instead of the occasional feast, if you get my drift. What I have been doing for the last 25+ years and which works very well for me and what seems to produce the biggest blooms on plants that don't completely exhaust themselves and end up a sickly yellow by harvest time, is to continue with grow nutrients for the first 2 weeks of flowering, then change to half grow and half bloom for the next 2 weeks, before changing to straight bloom nutrients through until maturity. This may be something you might like to try on your next grow? I guarantee it works, but remember, half strength to three quarters strength is usually plenty strong enough. So when mixing half grow and half bloom, it is one quarter strength of each, that when added together, will give you half strength. Anyway, a dose or two of half strength grow nutrients should return your plants to good health once again and put them on the path to growing their best flowers too. It is very easy to fix a slight under feeding, but very hard to rescue a badly burned and damaged, over fed plant! Hope this helps, Organoman.

I have used fox farm too, can agree that it's strong, but to me personally it looks like hunger. When you train your plant, they loose that balance of storage, so instead of moving muted from few worthless bottom leaves ....

I use a pH pen to check the water is around 6, I'll start double-checking with actual pH test strips from now on

Those nutes are good but very strong if used according to the recommendation on bottles.. Also tiger bloom tanks my pH if I use more than 5-7 ml a gallon. You using pH and Ec pen?